#include <stdio.h>

int main(void)
{
    int day = 0;
    switch(day)
    {
        case 1:
            printf("monday\n");
            break;
        case 2:
            printf("tuesday\n");
            break;
        case 3:
            printf("thursday\n");
            break;
    }
    return 0;
}

int main()
{
    int n = 1;
    int m = 2;
    switch (n)
    {
        case 1:
            m++;
        case 2:
            n++;
        case 3:
            switch(n)
            {
                case 1:
                    n++;
                case 2:
                    m++;
                    n++;
                    break;
            }
        case 4:
            m++;
            break;
        default:
            break;
    }
    printf("m=%d,n=%d",m,n);
    return 0;
}

int main()
{
    int i = 1;
    while(i<=10)
    {
        if(i==5)
        {
            break;
            printf("%d",i);
            i=i+1;
        }
    }
}

int main()
{
    int ch = 0;
    while((ch=getchar())!=EOF)
    {
        putchar(ch);
    }
    return 0;
}

int main()
{
    char ch = '\0';
    while((ch=getchar())!=EOF)
    {
        if(ch<'0'||ch>'9')
            continue;
        putchar(ch);
    }
    return 0;
}
